Innovating Energy Management, Strengthening Technological Transformation

Shougang Co., Ltd. has improved the utilization rate of its water resources and enhanced its water-saving capacity. This was achieved through a series of measures including innovative energy management, water-saving technology transformation, implementing water quotas in work processes, and wastewater reuse. Only 2.5 cubic meters of new water is now consumed per ton of steel. The company achieves ‘zero’ discharge of water used in production, achieving an environmental management system certification and an energy management system certification across all of its processes. Because of its outstanding performance in water treatment, Shougang has been rated as a provincial water-saving demonstration enterprise in Hebei Province and a municipal water-saving enterprise in Tangshan City.

Continuing to carry out water-saving technological innovations. In accordance with the concept of the circular economy and the requirements of clean production, Shougang has improved its processes and level of technical sophistication, strengthened its water-saving and wastewater resource utilization, and improved its advanced sewage treatment capacity. Equipped with a complete set of water treatment facilities, the company can fully treat the wastewater from each of its production processes. The sewage treatment station and advanced treatment station system collect all domestic sewage, production sewage, and various types of wastewater generated by the entire plant and independently treat it, producing water that meets the standard for reuse in production. The company recycles all reclaimed water after treatment, having upgraded its water treatment process and adopted double membrane method advanced treatment technology. The desalinated water generated by this process is used in a closed circulating water system, a vaporization cooling system and for rinsing and spraying in a number of processes including iron making, steel making, hot rolling, cold rolling, power generation and oxygen production. For brine that cannot meet discharge standards or the requirements of recycling and reuse, the company adopts a concentrated water reverse osmosis treatment process to further concentrate and reduce the brine, and then use it for blast furnace slag flushing, stewing slag and sintering mixtures to achieve close to zero discharge of concentrated brine. Shougang also uses innovative water quality stabilization technology to overcome a number of problems associated with brine, including corrosion, scaling and chemical instability in high-temperature environments. Long-term stability of brine is achieved for use in blast furnace slag flushing, opening up a new direction for better brine management within the industry. The company also comprehensively optimized its low-quality wastewater discharge system while establishing a drainage pipe network water quantity and quality monitoring system. According to the generation of low-quality wastewater and its quality, the company has established an independent pipeline to a consumable system to recycle this low-quality wastewater.

Improving its scientific water management system. Shougang has established a relatively complete basic water management system, achieving effective implementation and management of process-wide indicators. By constructing a four-level management system for water supply and drainage in the company, spanning function departments, operation departments and operation areas, the company strengthens efficient collaboration and enhances management execution. This allows for various problems in the operation of the water system to be resolved quickly and targeted measures and plans to be formulated in a timely manner, making use of the synergy of the team and resolving problems across departments to achieve stable and efficient water usage and drainage throughout the process, and create excellent technical and economic indicators. The company also improves water use efficiency through quota management of process water. Having conducted research on water use in various processes and in-depth analysis of water use structures, processes and technologies, the company has formulated process water quotas based on national and industrial standards and production process characteristics, achieving full-process management based on process water use indicators. The company also uses a secondary energy system to establish a dynamic information platform for water use indicators, and has developed a water supply app to achieve refined control of circulating water quality. The company implements full-process control of production wastewater discharge, effectively systematizing production wastewater discharge and improving stability of water quality. If problems are found via the online drainage monitoring system, the company is able to take emergency measures to avoid the paralysis of the in-depth treatment system and environmental accidents, thus guaranteeing a safe production environment and outer drainage discharge compliance.